EFFECT OF BIS (TRIETHOXYSILYLPROPYL) TETRASULFIDE ON PHYSICAL PROPERTIES OF RICE HUSK FIBER/NATURAL RUBBER COMPOSITES

In this study, rice husk fiber (RHF), a byproduct from rice milling process, was used as reinforcing filler for natural rubber (NR). Generally, REF surface and NR have different polarity. Therefore, fiber surface treatment was employed in this work to improve compatibility between REF and NR. RHF was pretreated with alkali solution for 2 h (2ALT) before treating with various bis (triethoxysilylpropyl) tetrasulfide (TESPT) contents, i.e., 2, 5 and 10 wt% relative to RHF content. Physical properties of REF and RHF/NR composites were characterized. FTIR spectra of TESPT treated REF (ST) confirmed the appearance of TESPT on REF surface. Additionally, the observed TESPT amount on the REF surface increased with increasing treated TESPT content. For NR composites, scorch time of ST/NR composites was longer than that of 2ALT/NR composites. With increasing TESPT content, there was no changed in scorch time of NR composites. ST/NR composites showed the maximum values of M100, M300, tensile strength and tear strength at TESPT content of 5 wt% indicating the improvement of rubber-fiber interaction and fiber dispersion in NR matrix.